Graphics Interchange Format, GIF (CompuServe GIF) is a graphics format widely used on the World Wide Web, both for images and for animations. The format was developed by CompuServe in 1987 to provide a color image format for their file downloading areas, replacing their earlier RLE format in black and white. GIF became popular because they could use the LZW compression algorithm (Lempel Ziv Welch) for compressing the image, which was more efficient than the algorithm Run-length encoding (RLE) used by the PCX and MacPaint formats. Therefore, large images could be downloaded in a reasonable period of time, even with very slow modems.
In computing, JPEG (seen most often with the .jpg or.jpeg filename extension) is a commonly used method of lossy compressionfor digital images, particularly for those images produced by digital photography. The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and image quality. JPEG typically achieves 10:1 compression with little perceptible loss in image quality. JPEG compression is used in a number of image file formats. JPEG/Exif is the most common image format used by digital cameras and other photographic image capture devices; along with JPEG/JFIF, it is the most common format for storing and transmitting photographic images on the World Wide Web.